Google has a habit of cleaning up after Microsoft's mess. At least, that's what Sergey, Larry and Eric would like you to believe.

Not long ago, Google released Chrome Frame, which superimposes Google browser technology onto Internet Explorer, which either brings IE6, 7 and 8 into the modern age or doubles its attack surface, depending on whether you believe Google or Microsoft. Now Google is taking a similar approach to enterprise e-mail, another market in which Google's share is dwarfed by the incumbent Microsoft.

Google today announced "Google Message Continuity," saying the new service will "bring Gmail's reliabilty to Microsoft Exchange."

It's "a new email continuity service that can help you ensure that your users never lose access to email during a Microsoft Exchange outage, whether planned or unplanned," Google wrote on its official blog. "By synchronizing your on-premises accounts with Google's cloud, Google Message Continuity gives you access to your up-to-date email inboxes through the Gmail interface) no matter what happens to your on-premises servers. And once your servers come back up after an outage, messages sent and received, plus message state changes (like deletions and folder assignments) that are recorded ... during the outage are then synchronized with your servers."

Outages in Gmail itself seemed to be commonplace in 2008 and 2009, but to be fair Google's webmail service has been more reliable lately. The Message Continuity service, part of Postini, does seem useful at first glance and will cost $25 per user per year (or an extra $13 for current Postini customers).

Like Chrome Frame on Internet Explorer, the service is not for the newest version of Microsoft's software. In this case, the message continuity service will work with Exchange 2003 and 2007.

Third-party companies selling products that bolster management capabilities of Exchange are nothing new, so in that sense Google is acting as just another part of what Microsoft might call its "ecosystem." That's the message Microsoft sent in its response to Google's announcement, noting that "businesses rely on Exchange more than any other messaging solution because of its enterprise grade management and security," but that customers also "benefit from the large ecosystem of hundreds of third party solutions that extend and complement Exchange." With today's announcement "Google joins an existing list of email continuity providers for Exchange," Microsoft said in a statement to Network World.

But Google is also different from most service providers because it is trying to lure customers away from Exchange entirely, and by giving businesses an option to use Exchange and Gmail together, Google is hoping customers may decide to switch to Gmail for good.

Google has complained in cases when it felt government agencies were not giving Google Apps a fair shot, but the company still has to prove itself in the enterprise market that Microsoft has long dominated. Google Message Continuity may be one step in the right direction.